Allington ( Grey Wolf ) has concocted an entertaining WW II thriller which follows the adventures of Derek Carr, a gambler and former arms smuggler blackmailed into working for British intelligence. Carr's task: to penetrate a German commando operation led by a Cambridge-educated scholar and soldier named Kordt. Kordt's mission, ``China Blue,'' is to cache munitions in India for use by invading Japanese forces now poised on the border. With Kordt is the historical figure of the independence fighter, Subhas Chandra Bose, accompanied by members of his nascent anti-British Indian National Army. Carr infiltrates ``China Blue'' through a wealthy Anglo-Indian beauty, Ashley Vora, a fervent supporter of Bose. Their affair is unconventional enough to serve as a welcome break from the unrelenting tension of the main plot and the more ambiguous relationship between Carr and Kordt. Allington's descriptions of Carr's escape from a German dungeon guarded by cobras, of his epic fight to the death with Kordt's seven-foot bodyguard and of the climactic confrontation between hero and villain after the German has single-handedly destroyed the Bombay docks, are riproaring stuff, stylishly written. Fine background detail adds depth to this engrossing thriller as Allington also evokes the beauty, poverty and mystery of India. (Mar.)